The JT-60SA tokamak, the world's largest and most advanced superconducting fusion experiment currently in operation, achieved first plasma on October 26, 2023, at its site in Naka, Japan. The milestone, formally announced at an inauguration ceremony on December 1, 2023, represents a significant achievement for the international collaboration between Europe's Fusion for Energy (F4E) and Japan's National Institutes for Quantum Science and Technology (QST). This event signals the start of the experimental phase for a device designed to investigate sustained, high-performance plasma scenarios critical for future fusion power plants and to provide operational support for the larger ITER project under construction in France. Source: Newatlas

Engineered as an upgrade to the previous JT-60U machine, JT-60SA is a substantial device standing 15.5 meters tall with a plasma volume of 135 cubic meters. Its magnetic confinement system utilizes niobium-titanium superconductors to generate the powerful fields necessary to contain and shape the plasma. The machine is designed to drive a plasma current of 5.5 million amperes and heat the plasma to a target temperature of 200 million degrees Celsius. A key objective is to sustain these high-temperature plasmas for durations of up to 100 seconds, a significant step beyond the pulse lengths of most previous tokamaks and a crucial requirement for net-energy-gain reactors. Source: Newatlas

Engineered as an upgrade to the previous JT-60U machine, JT-60SA is a substantial device standing 15.5 meters tall with a plasma volume of 135 cubic meters.

The strategic role of JT-60SA is twofold: to de-risk operations for ITER and to accelerate the development of a demonstration power plant (DEMO). As a satellite tokamak, it will test operational scenarios, plasma control schemes, and hardware components under conditions relevant to ITER, but with greater experimental flexibility and before ITER's own D-T campaigns begin. The data gathered from JT-60SA's hydrogen and deuterium campaigns will inform ITER's operational strategies, helping to optimize performance and component lifetime in the larger machine. This parallel research path is a core element of the global strategy to advance fusion science. Source: Newatlas

The project's timeline highlights the complexity of constructing such a large-scale international research facility. Following an agreement signed in 2007, construction began, with assembly of the tokamak completed in 2020. The subsequent years were dedicated to a rigorous series of integrated commissioning tests, verifying the functionality of the vacuum vessel, cryogenics, and the powerful superconducting magnet systems before the first plasma attempt. The successful initiation of plasma operations validates over a decade of design, manufacturing, and assembly work contributed by research institutions and industrial partners across Europe and Japan. Source: Newatlas

With commissioning now complete, the JT-60SA research program will proceed with progressively increasing plasma performance. Initial experiments will focus on hydrogen and later deuterium plasmas to characterize the device and refine control techniques. These campaigns will provide critical data on plasma stability, heat exhaust management, and confinement physics in a reactor-scale superconducting device. The operational experience gained will be invaluable for the broader fusion community, particularly for the teams preparing for the eventual operation of ITER and the design of subsequent commercial-scale reactors. Source: Newatlas